AFAIK, PDF is mostly a container for PS with compression and better handling of fonts (BTW, can fonts be embedded in PS? How fonts are sent to printer?). Still

AFAIK, PDF is mostly a container for PS with compression and better handling of fonts (BTW, can fonts be embedded in PS? How fonts are sent to printer?). Still, both formats are too much printing-oriented. Reading documentation in PDF on computer screen is not especially pleasant, and unbearable on phones.